Roller structure for lift truck carriages



Aug. 11, 1953 J. A. FRISCHMANN I ROLLER STRUCTURE FOR LIFT TRUCK CARRIAGES Filed March 31, 1951 2 Sheets-Sheet l IN V EN TOR. JOSEPH A. FE/SCHMA/W M? a m A TTO/QA/E Y5 Aug. 11, 1953 J. A. FRISCHMANN ROLLER STRUCTURE FOR LIFT TRUCK CARRIAGES Filed March 31, 1951 2 Sheets-Sheet 2 INVENTOR. JOSEPH A. FELSCHMANN BY KM ATTORNEYS Patented Aug. 11, 1953 R'OI-JIIER STRUCTURE FOR LIFT TRUCK CARRIAGES Joseph 'Frischmann, Cleveland, Ohio, assignor to To'wmotor Corporation, Cleveland, Ohio, a

corporation of hio Application Ma-rch3-1, 1951,Seria1No. 218,655

"1 This invention relates to lifttrucks of the type that embody a load-carrying carriage for vertical reciprocation on a mast of channel construction, and, more particularly, to guide roller arrangements for reducing the friction and improving the operational characteristics as the carriage travels along the mast.

In the operation of lift trucks, it is often necessary'to lift loads of appreciable weight, and the placing of the loads on the 'carriage'is sometimes eccentric to a "considerable degree. Such eccentric loading places a great burden on the .guide mechanism which holds thecarriage as it travels along the mast. Failures in the guide mechanism have occurred due to lack of strength which results from a conventional arrangement of rollers and pintles for attaching the rollers to the carriage. High stresses on roller structures often cause the'roller to slide, thereby producing a flat side on the roller and'rende'ring the structure'inoperable as an ahtifricti'on bearing means.

Sliding of the roller causes scoring and seizing of the slide mechanism which is deleterious to the operation of the machine.

It is an object of this invention toprovide a roller structure which is capable of carrying high loads without binding or distortion and-is reasonably free from maintenance requirements.

Another object of this invention is to provide a roller structurefor carryingtlie"carriage along the mast which has'a support member for holding the pin on which the rollerro'ta'tes at the outer end for preventing bending which results when the pin is in cantilever relationship with the carriage.

A still further object of this invention is to provide a slide associated with the pin and roller structure for engagement withthe channel to prevent movement of the carriage in a lateral direction as it moves along the mast.

Other objects and advantages, more'or less ancillary to the foregoing, and the manner-in which all the various objects are realized will appear in the following description, which, considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

In the drawings:

Fig. 1 is a side elevational view of the carriage and mast structure mounted on the conventional lift truck;

Fig. 2 is a detail of the roller structure with parts cut away to show details of construction;

Fig. 3 is an end view of the roller mounting; and

with the yoke and carriage. head'M' is formedwon the end: oftheipinj 2B, the plane of the suria'ce onithe: heads34 being normal to the centerline .of the .pin1-28. -isin "sliding engagement with the. inner surface of the web ofthe channelld whenthedoadon thecarrlagei causesithecarriageto shift laterally. Adj'ustment of fthe height .of :the head :3il rela- Fig. 4 is a side view of the roller mounting as it is associated with "the channel members of the mast.

Referring first to 'Fig. l, the numeral "l-D designates alift truck vehicle having a vertical mast I2 attached to the forward end thereof. "The mast i2 is formed by two pairs of channel members opening toward each'oth'er, channel M be-- 'ing slidable inside of channel -16. A carriage 18 is mounted on the mast for v'erticalrec'iprocation and carries a fork 2 0 on which the load is deposited during operation. A cylinder and chain assembly 22 havinga controllable hydrau 'lic fluid supply'under pressure supplies the necessary lifting force for raising thecarriage [B when the load is-on the fork '20.

At each sideof-thecarriage 18,- a pair-of rollers 24 is'attached for travel in'a vertical-path internally of channel I 4. l ne-rollers" 2 4 are/spaced apart vertically to -'overcome the moment intro- 'duced'by the load being carried-on the forks 2'20.

The structure provided for rotatably .mounting the roller 24. on the-carriageincludes-ayoke :26 which is a'ffixe'd to the-carriage 18. The yoke 26 has an opening formed therein .inrialigmnent with an'opening in the carriage H3 which 11'8- ceivesa pin 28. -A rollerloearing 30 is located intermediate the roller 24 and the v.pin .28 for carrying the roller with a minimum :of. friction. A pair of thrust washers 32 areilocatedrateach side of the roller 24 for positioning the roller relative to the carriage I18 "andnthe .yOkeJZB .and

'for 'holding'the roller 524 out of sliding contact .Aflat elongated The, head 134 tive to: the carriage l8 .is':provided:by a, plurality of shims 36 located between the head 34 and the yoke 26. By introducing the proper number of shims, lateral movement of the carriage may be reduced to a minimum and the necessary freedom for slidin may be retained.

A drilled passage 38 in the pin 28 communicates with the bearing 30 and with the end of the pin 28 opposite to head 34 wherein a greasing fitting 40 is affixed. Grease, introduced into fitting 40 by a conventional grease gun, will reach the bearing and thereby lubricate the roller as it travels along the channel M.

A pair of ridges 42, parallel to the longitudinal 3 axis of the head 34, restrains the pin 28 from rotative movement when the roller turns thereon. It may be noted that no nut or keeper is required for the pin 28 since the assembly cannot move out of position when the carriage has been placed in the operating position on the mast.

In operation, the carriage is caused to traverse the mast through actuation by the hydraulic cylinder assembly and carries the load on the :fork 20 as required by the use of the vehicle. The rollers 24 travel vertically in the channel I4 and roll on the inner walls of the flange sections on the channel [4 as required by the load and forces applied to the carriage IS. The upper rollers 24 roll on the forward flange while the lower rollers 24 operate on the rearward flange of the channel l4. Cantilever bending of the pin for support of the roller is eliminated by the yoke 26 which carries the outer end of the pin 28. By this arrangement, the roller will roll straight and true, the axis of rotation being always parallel to the surface on which the roller runs. The rollers, therefore, guide the carriage in a fore and aft direction and provide a friction free means of restraining the carriage to a predetermined path of travel.

When loads applied to the carriage are off center, the carriage has a tendency to move toward one Side of the mast. This results in the carriage structure bearing against the mast which must be over-come by suitable means such as the flattened head 34 of the pin 28. The broad surface of the head 34 carries the side load which results from the eccentric load on the carriage as the carriage moves vertically in the mast. To obtain the proper distance between the outer faces of the heads 34 on the opposite sides of the carriage, shims 36 may be added between the heads 34 and the yokes 26 to obtain the dimension required to eliminate unnecessary looseness and .play. The use of the flat head 34 overcomes the difiiculties attendant with the operation of rollers for carrying the side loading.

It is to be understood that the specific nature of the present disclosure is not intended to be restrictive or confining and that various rearrangements of parts and modifications of design may be resorted to without departing from the scope or spirit of the invention as herein claimed.

What is claimed is:

1. In a lift truck having a mast with opposed vertical channel members opening toward each other, a carriage for vertical reciprocation on said mast, a guide member on the carriage, and guide means on the guide member for engagement with the channel, said means comprising a pin projecting from the guide member, a yoke affixed to the guide member and carrying the free end of said pin, and a roller on said pin intermediate the yoke and the guide member for 2. In a lift truck having a mast with opposed vertical channel members opening toward each other, a carriage for vertical reciprocation on said members, guide means on the carriage for engagement with the channel members, said means comprising a pin projecting from the carragie, a yoke aflixed to the carriage and carrying the free end of said pin, and a roller on said pin intermediate the yoke and the carriage for movement along the channel member whereby the carriage is positioned relative to the channel members as the carriage moves along its path of travel.

3. In a mast and carriage structure for a lift truck having opposed vertical channel members opening toward each other, a carriage for vertical reciprocation on said channel members, guide means on thecarriage for engagement with the channel, said means comprising a pin projecting from the carriage, a yoke aflixed to the guide member and carrying the free end of said pin, and a roller on said pin intermediate the yoke and the guide member for positioning the carriage relative to the channel members as the carriage moves along its path of travel.

4. In a mast and carriage structure for a lift truck, guide means for shiftably carrying the carriage along the mast comprising a pin projecting from the carriage, a yoke afiixed to the carriage and carrying the free end of said pin, a roller on said pin engageable with the mast, and a head on the pin for sliding engagement with the mast for positioning the carriage laterally relative to the mast.

5. In a mast and carriage structure for a lift truck, guide means for shiftably carrying the carriage along the mast comprising a pin projecting from the carriage, a yoke affixed to the carriage and carrying the free end of said pin, a roller on said pin engageable with the mast, and a flat elongated head on the pin for sliding engagement with the mast whereby the carriage is positioned laterally relative to the mast.

6. In a mast and carriage structure for a lift truck, guide means for shiftably carrying the carriage along the mast comprising a pin projecting from the carriage, a yoke affixed to the carriage and carrying the free end of said pin, a roller on said pin engageable with the mast, a head on the pin for sliding engagement with the mast for positioning the carriage laterally relapositioning. the carriage relative to the mast as the carriage moves along its path of travel.

tive to the mast, and a shoulder on the yoke adjacent the head of the pin for preventing rotation of the pin as the roller rotates relative to the carriage.

JOSEPH A. FRISCHMANN.

Number Date 2,480,056 Weaver Aug. 23, 1949 2,505,009 Schroeder Apr. 25, 1950 

